Screw-driver



(No Model.)

G. W. JAGKMAN.

' SCREW DRIVER.

No. 306,491. Patented 001:. 14, 1884.

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GEORGE \V. JAOKMAN, OF LITTLETLON, NE\V HAMPSHIRE.

SCREW DRIVER.

SPECIFICATION forming part of Letters Patent No. 306,491, dated October 14, 1884.

Application filed February 16, 1884.

To all whom, it may concern:

Be it known that I, GEORGE W. J AOKMAN, of the village of Littleton, in the county of Grafton and State of New Hampshire, have invented a new and useful Improvement in Screw-Drivers, of which the following is a specification.

The invention relates to the means by which screw-drivers may be made to grasp and hold screws preparatory to and while being driven; and it consists in adapting and ad justing thejaws of the screw-driver to enter necks and clasp spines in the heads of screws, and thereby securely hold the latter. It is designed especially for screws invented by me, for which invention a patent was allowed July 8, 1884; but it may be applied to bolts and all other articles having heads similarly constructed and admitting of being clasped, held, and driven. into position by the like means.

In the accompanying drawings, in which similar letters of reference indicate like parts. Figure 1 represents a screw-driver engaged with a screw as contemplated by my invention. A represents the handle; B B, the two jaws, which are made integral with the shank or tang that enters the handle, said jaws having lateral notches a a on the inner side of their lower extremities to embrace corresponding parts of the spine in the screw-head; and G, a lever rigidly attached to one of the jaws, and made integral therewith, by means whereof thejaws may be forced apart, so as to admit of their extremities being introduced into the nicks in the screwhead, and made to clasp and hold the spine therein. D is a slide for confining the end of the lever when required. E indicates the screw; 1) Z), nicks in its head; 0, the spine formed by the nicks on either side thereof, which are sunk into the top of the screwhead, extend across it, and are widened at bottom, as shown, in such manner as toleave a spine between them, also extending across the top of the screw-head and having a notch in each side below the crown. 0 indicates the crown, and c the base of the spine.

(No model.)

Fig. 2 represents a section of a screw-head transverse to the nicks and spine, and shows on a larger scale the engagement of the screwdriver with the screw in the same manner as is shown in Fig. 1.

Fig. 3 represents a like section of the screwhead and a like engagement of the screwdriver with the screw, except that here the notches in the extremities of the jaws, instead of being rectangular, are triangular in out line to adapt them to corresponding variations in the form of the spine. The jaws of the screw-driver are held together by force of the spring in the material of which they are composed, but are capable of being forced apart by means of the lever.

The jaws in the several figures of the drawings are represented with rectangular or trilangularnotches in their extremities; but, instead of these, grooves or recesses of any suitable form may be employed.

The advantage claimed for this invention is its adaptation to grasp, hold, and control a Screw formed as described, and control the S me while being applied to the object into which it is desired to insert it, and while it is being driven into its intended position, and to accomplish this with little danger of rap turing the screw-head.

What is claimed as patentable in this invention is A screw-driver having a pair of jaws made integral with the shank or tang that enters the handle, the said jaws having lateral grooves or recesses on the inner side of their lower extremities, and being capableof being forced apart by means of a lever rigidly attached to one of the jaws and made integral therewith, all substantially as set forth and described.

GEORGE V. JACKMAN.

\Vi tnesses:

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